Okay so I was just wondering that if I want to purchase a Galaxy S7 Edge from Ebay, why does it have to be GSM935-U? I have a friend who purchased a galaxy that was GSM935-V and it worked well with the Republic Wireless network. It’s also a cheaper alternative to GSM935-U.

Your friend using the “V” version of the phone is both lucky (and likely only temporarily) and violating the Republic TOS. Using any phone other than the supported version is prohibited and shouldn’t work, but sometimes things slip through the cracks, until they don’t anymore. While the phone may appear to be operating properly to the user, this does not mean it is operating properly in its interaction with the network. If it turns out that it is utilizing the underlying carrier services rather than Republic’s (which is usually the issue) then Republic will eventually detect it and can take action from politely warning to user to terminating the service without warning.